The studies proposed in this application will: (1) determine if progesterone withdrawal at different stages of decidualization would affect the expression of bcl-2 gene family members; this information will be correlated with DNA fragmentation in the decidual cells; (2) investigate why induced Bax expression failed to cause death of decidual cells by determining if Bax activity is compromised by Bcl-xL or hsp-25; (3) determine the expression of TGF-beta and apoptotic mediators (cathepsin-D, cytochrome- c, apaf-1, and caspase-3) in the GG-AD decidual cell line, and assess the consequence of overexpressing bax or inhibiting bax and cathepsin-D in GG-AD cells.